Toss that syn fuel -- it will wreck your FP very quickly.

The FP is a plain-bearing motor (no ball bearings) and synthetic oil just isn't up to the job when it comes to lubricating the crankshaft.

Within no time, the hole in which the crankshaft runs will oval and you'll start losing crankcase compression -- which means the engine will run erratically and lose power.

Plain bearing (bushed) motors *must* be run on fuel that has a very healthy amount of castor oil in it. At the *very* least you ought to use something like Omega.

Also try dropping your nitro content. While the FP series would tollerate up to 10% or so nitro, they much preferred a low nitro fuel.

And throw an OS#8 plug in that engine -- it's the *perfect* plug for it.